1. Field of the Invention
The present invention relates to a center take-off rack-and-pinion steering apparatus.
2. Description of Related Art
Examples of a steering apparatus include a so-called center take-off steering apparatus. In this type of steering apparatus, a tie rod connected to a wheel is taken out of a rack shaft at a central position in a right-and-left direction of a vehicle body. For example, a steering mechanism includes a rack shaft and a longitudinal cylindrical rack housing receiving the rack shaft. An elongate hole is formed in an intermediate portion of the rack housing in a longitudinal direction. Through the elongate hole, the rack shaft and the tie rod are connected to each other through a slider. The rack housing and the slider are brought into sliding contact with each other (see Japanese Unexamined Patent Publication Nos. 2000-62628 and 2001-151140).
In Japanese Unexamined Patent Publication No. 2000-62628, the rack housing includes a flat first sliding contact surface formed in the inner periphery of the elongate hole and a flat second sliding contact surface formed at an edge surrounding the elongate hole on an outer peripheral surface of the rack housing.
Furthermore, the slider has flat first and flat second sliding contact surfaces that are individually brought into sliding contact with the first and second sliding contact surfaces of the rack housing. The first sliding contact surface of the rack housing extends parallel to the longitudinal direction and a depth direction of the elongate hole. The second sliding contact surface of the rack housing is perpendicular to the first sliding contact surface of the rack housing.
In Japanese Unexamined Patent Publication No. 2000-62628, the first and second sliding contact surfaces that are perpendicular to each other are provided, so that the manufacturing cost of the steering apparatus is high.